Lavatory system

ABSTRACT

A lavatory system having at least one wash station and at least one electrically operated fixture is disclosed. The lavatory system includes a control system for operating the at least one electrically operated fixture. The control system comprises a power supply system, a detection system, and a fixture actuation system. According to one embodiment, the detection system comprises a processor, a sensor configured to detect a user within a sensing region, and a sampling circuit configured to store a signal from the sensor that is used by the processor to activate the fixture. According to another embodiment, the power supply system includes a power source providing an output voltage for operating components of the control system, a detector monitoring the output voltage, and a switch for electrically disconnecting the power source from the components of the control system if the output voltage drops below a predetermined level. According to one embodiment, the power source is at least one photovoltaic cell coupled to the lavatory system.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the benefit under 35 U.S.C. 119(e) of U.S.Provisional Application No. 60/538,583, having a filing date of Jan. 23,2004, titled “LAVATORY SYSTEM,” and U.S. Provisional Application No.60/602,585, having a filing date of Aug. 18, 2004, titled “LAVATORYSYSTEM,” the disclosures of which are hereby incorporated by reference.

FIELD

The present inventions relate generally to a lavatory system. Thepresent inventions also relate to a lavatory system having a controlsystem suitable for providing “hands-free” operation of one or morefixtures (e.g., sprayheads, faucets, showerheads, soap or lotiondispensers, hand dryers, flushers for toilets and/or urinals, emergencyfixtures, etc.) within the lavatory system. The present inventionsfurther relate to a lavatory system having a photovoltaic system forproviding electrical energy one or more electronic fixtures within thelavatory system and/or for providing electrical energy to a controlsystem coupled to the fixtures.

BACKGROUND

It is generally known to provide a lavatory system having at least onefixture that conventionally requires manual manipulation by a user inorder to operate. It is further known to provide an electrical and/orelectronic control system with such a fixture for providing “hands-free”operation of the fixture. Not requiring a user to physically contact ortouch the fixture for its operation may be desirable for varioussanitary and/or accessibility considerations.

A power source is necessary when using an electronic and/or electricalcontrol system to control a fixture. When available and desirable, poweris commonly provided by an AC power line. However, when not available ornot desirable, alternative power sources are utilized. Known alternativepower sources include energy storage elements such as batteries andcapacitors. However, control systems that use such energy storageelements have disadvantages, including having a power source with arelatively finite operating life that often must be periodicallychanged, reenergized, or otherwise maintained.

It would be advantageous to provide a lavatory system for use incommercial, educational, or residential applications, having one or morefixtures and a control system for enabling “hands-free” operation of thefixtures wherein the control system is powered by means other than an ACpower line (e.g., energy storage element, etc.). It would also beadvantageous to provide a control system for use with a lavatory systemthat can prolong the operating life of an energy storage element byreducing or minimizing the required power consumption of the controlsystem. It would further be advantageous to provide a control systemthat minimizes or reduces power consumption by increasing the speed atwhich the control system processes a signal representative of theenvironment near the fixture (a sensing region). It would further beadvantageous to provide a lavatory system having a photovoltaic systemthat can provide electrical energy to a control system and/or a fixtureof the lavatory system. It would further be advantageous to incorporatephotovoltaic cells into the support structure of a lavatory system (suchas a usable surface). It would further be advantageous to provide apower management system providing for the efficient use of electricalenergy generated by a photovoltaic system.

Accordingly, it would be desirable to provide for a lavatory systemhaving one or more of these or other advantageous features.

SUMMARY

The present invention relates to a control system for use with alavatory system for use by a user having at least one wash station andat least one electrically operated fixture. The control system includesa detection system including a control circuit configured to operateduring a first period during which a sensing region is monitored for thepresence of the user followed by a second period during which powerconsumption by the control circuit is reduced, and a fixture actuationsystem coupled to the detection system and configured to control theflow of a fluid through the fixture based upon a signal received fromthe control circuit during the first period. The second period isgreater than the first period so that total power consumption by thecontrol circuit can be reduced.

The present invention also relates to control system including a controlcircuit, a sensor coupled to the control circuit and including atransmitter and a receiver configured to the user within a sensingregion, and a sampling circuit coupled to the control circuit and thesensor and configured to store a first signal and a second signal fromthe receiver. A difference between the first signal and the secondsignal is received by the control circuit for determining whether toactivate the fixture.

The present invention further relates to a power supply system for alavatory system having a control system for operating a fixture. Thepower supply system includes a power source configured to beelectrically coupled to the control system and to provide an outputvoltage, a detector configured to monitor the output voltage of thepower source, and a switch configured to electrically disconnect thepower source from the control system when the output voltage of thepower source drops below a predetermined level.

The present invention further relates to a lavatory system. The lavatorysystem includes a lavatory providing at least one wash station andhaving at least one basin and at least one fixture, a control system forcontrolling the flow of fluid to the at least one fixture, and an arrayof photovoltaic cells coupled to the lavatory and configured to providepower to the at least one fixture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a lavatory system according to anexemplary embodiment, shown as a washing station.

FIG. 2 is a perspective view of a lavatory system having a photovoltaicsystem according to an exemplary embodiment.

FIG. 3 is a top view of the lavatory system of FIG. 2 showingphotovoltaic cells coupled to an upper portion of the lavatory system.

FIG. 4 is a partially exploded perspective view of the photovoltaicsystem of FIG. 2.

FIG. 5 is a partial cross section view of the lavatory system shown inFIG. 2 taken along the line 5-5.

FIG. 6 is an exploded perspective view of an upper portion of a lavatorysystem showing a photovoltaic system according to another embodiment.

FIG. 7 is a partial cross section of the upper portion of the lavatorysystem shown in FIG. 6 showing a photovoltaic cell unit coupled to thelavatory system.

FIG. 8 is a schematic block diagram a control system for use with thelavatory system shown in FIG. 1 to provide for the operation of thefixtures.

FIG. 9 is a schematic block diagram of a power supply system of thecontrol system shown schematically in FIG. 8 according to an exemplaryembodiment.

FIG. 10 is a schematic block diagram of a power supply system of thecontrol system shown schematically in FIG. 8 according to anotherexemplary embodiment.

FIG. 11 is a schematic block diagram of a detection system of thecontrol system shown schematically in FIG. 8 according to an exemplaryembodiment.

FIG. 12 is a schematic block diagram of a transmitter of the controlsystem shown schematically in FIG. 11 according to an exemplaryembodiment.

FIG. 13 is a schematic block diagram of a receiver of the control systemshown schematically in FIG. 11 according to an exemplary embodiment.

FIG. 14 is a schematic block diagram of a fixture actuation system ofthe control system shown schematically in FIG. 8 according to anexemplary embodiment.

FIG. 15 is a detailed schematic block diagram of the control system ofFIG. 8 according to an exemplary embodiment.

FIG. 16 is a detailed schematic block diagram of the control system ofFIG. 8 according to another exemplary embodiment.

FIG. 17 is a detailed schematic block diagram of a power managementsystem of the photovoltaic system of FIG. 16 according to an exemplaryembodiment.

DETAILED DESCRIPTION

Referring generally to the FIGURES, a lavatory system 10 with componentsis shown according to exemplary embodiments. FIG. 1 shows lavatorysystem 10 as a washing station suitable for providing a cleansing areafor one or more users. Lavatory system 10 is shown as including a pairof fixtures 14 having outlets (e.g., nozzles, diffusers, etc.) directedtowards a basin 18 which is supported by a base or a support structure12. Support structure 12 is provided an upper portion 16 by whichfixtures 14, and/or other components, may be placed upon or coupledthereto. Upper portion 16 is further shown as including a platform orshelf 20 which provides a relatively flat surface (e.g., ledge,countertop, etc.) that can be used by a user to conveniently holdvarious objects (e.g., toiletries, beverage containers, personal items,etc.).

According to an exemplary embodiment, lavatory system 10 includes acontrol system 50 for controlling the operation of fixtures 14.Preferably, fixtures 14 are “touchless” fixtures meaning that a user canoperate the fixtures without physically contacting the fixtures and/oran interface coupled to the fixtures (i.e., “hands-free” operation). Inthis manner, lavatory system 10 can overcome sanitation and/oraccessibility limitations often associated with conventionally usedfixtures. Control system 50 monitors a defined sensing region (an areaadequately proximate to fixtures 14 in which a user of the fixture islikely to be positioned) for the presence of an object (e.g., a user,etc.) and controls the operation of fixtures 14 accordingly. FIG. 8shows a block diagram representative of control system 50 according toan exemplary embodiment. Control system 50 includes a power supplysystem 100, a detection system 200, and a fixture actuation system 500.Control system 50 is configured to reduce power consumption in an effortto prolong the useful operating life of a power source having an finiteoperating life (such as a battery). Power consumption is reduced byshortening the time interval (i.e., a sample period) for which detectionsystem 200 is monitoring the sensing region and by increasing a speed atwhich detection system 200 processes a signal representative of statusof the sensing region. Increased processing speed allows detectionsystem 200 to take extended “sleep periods” which conserve power. “Sleepperiods” include periods wherein detection system 200 is substantiallynot consuming any power, and/or periods wherein detection system 200 isconsuming a reduced amount of power.

According to another exemplary embodiment, lavatory system 10 includes aphotovoltaic system 600 capable of converting light energy to electricalenergy. Photovoltaic system 600 can be used to power fixtures 14 and/ora control system providing for the “hands-free” operation of fixtures 14(such as control system 50). FIGS. 2 through 4 and 16 through 18 showphotovoltaic system 600 and components thereof according to exemplaryembodiments. Referring particularly to FIG. 2, photovoltaic system 600is shown as including one or more photovoltaic cells 602 (such as anarray of cells) coupled to support structure 12 of lavatory system 10.Photovoltaic cells 602 may be supported by, mounted to, containedwithin, and/or integrally formed with a portion of support structure 12.Preferably, photovoltaic cells 602 are provided at shelf 20 of upperportion 16 of support structure 12 in an effort to maximize the exposureof photovoltaic cells 102 to the ambient light. Preferably, the additionof photovoltaic cells 602 to shelf 20 does not significantly limit thefunctionality of shelf 20 as a usable surface for a user.

Photovoltaic cells 602 are electrically coupled to fixtures 14 and/or acontrol system providing for the operation of fixtures 14. According toan exemplary embodiment, photovoltaic system 600 further includes apower management system 650 providing for an efficient use of theelectrical energy generated by photovoltaic cells 602. FIGS. 17 and 18show power management system 650 and components thereof according toexemplary embodiments. Power management system 650 generally includes anenergy storage element 660 configured to receive and store electricalenergy generated by photovoltaic cells 602, a detector (shown as avoltage detector 670) for monitoring the level of ambient lightsurrounding lavatory system 10 (e.g., by monitoring the energy stored inenergy storage element 660, etc.) to recognize periods of time when itis unlikely that lavatory system 10 will be used (e.g., when the ambientlight is turn off or otherwise reduced), a switch 680 capable ofelectrically disconnecting energy storage element 660 from controlsystem 50 when voltage detector 670 sends an output signal indicatingthat given the level of ambient light surrounding lavatory system 10 itis unlikely that lavatory system 10 will be used, and a voltageregulator 690 for adjusting the voltage being sent to control system 50.According to various alternative embodiments, power management systemmay be used without photovoltaic cells 602 to electrically disconnect anenergy storage element (such as a battery) from control system 50.

Referring back to FIG. 1, lavatory system 10, is intended forcommercial, educational, medical, and/or residential use and to bereadily installed in a number of locations and environments including,but not limited to, restrooms, locker rooms, break rooms, surgical preprooms, kitchens, or the like. For purpose of this disclosure, the phrase“lavatory system” is used generally to refer to any cleansing or othersanitary system or station, and is not intended to be limited to thewashing station shown. For example, the various alternative embodimentsof lavatory system 10 may include, but are not limited to, toilets,urinals, showers, wash fountains, emergency wash stations (e.g., drenchshowers, eye wash systems, etc.), or alternative washing stations.

Fixtures 14, shown as a pair of sprayheads, are configured fordirectionally dispensing (e.g., spraying, discharging, spending, etc.) afluid (e.g., water, etc.). According to various alternative embodiments,lavatory system 10 may include a variety of other fixtures instead of,or in combination with, fixtures 14 including, but not limited to,faucets, soap or lotion dispensers, hand dryers, showerheads, flushersfor toilets and/or urinals, emergency fixtures, etc. Fixtures 14 areshown coupled to support structure 12, but alternatively may besupported relative to lavatory system 10. For example, according to analternative embodiment, fixtures 14 may be coupled to a structure suchas a wall or partition rather than support structure 12. According to apreferred embodiment, fixtures 14 are coupled to upper portion 16 ofsupport structure 12 with their outlets directed in an outwardly anddownwardly manner towards basin 18.

Fixtures 14 are adapted for being in fluid communication with a fluidsupply via a conduit system (not shown) which is likely to include oneor more sections of piping or tubing. Each fixture 14 may beindependently coupled to a fluid supply, or alternatively, may becoupled to a common or shared fluid supply (e.g., through use of amanifold, etc.). Preferably lavatory system 10 is a multiple stationlavatory system wherein fixtures 14 are sufficiently spaced apart in alateral direction relative to support structure 12 for providing morethan one cleansing area. According to various alternative embodiments,any number of fixtures 14 may be used for providing any number ofcleansing areas.

Lavatory system 10 further includes a fluid collection receptacle (shownas wash basin 18) for collecting fluid that is discharged from fixtures14. Wash basin 18 is likely to include one or more fluid drains 19(shown in FIG. 3) which allow wash basin 18 to be emptied of fluidcollected therein. Preferably, wash basin 18 is a substantiallycontinuous receptacle for servicing both fixtures 14, but alternatively,may be provided as a divided receptacle, or further still, as twoseparate or isolated receptacles (one for each fixture 14). Wash basin18 is surrounded by a relatively flat surface (e.g., platform, ledge,countertop, tabletop, etc.), shown as a deck 17. Deck 17 may beintegrally formed with wash basin 18 (provided as a one-piece member),or alternatively, may be a separate component. According to variousalternative embodiments, fixtures 14 may be coupled to deck 17, whichcan also be used to support a variety of other fixtures. Wash basin 18is shown as being supported by support structure 12, but according to analternative embodiment, may be supported by a partition or any othersuitable wall structure.

Support structure 12 is shown as including upper portion 16 and a lowerportion 22. Upper portion 16 is positioned above wash basin 18 and isprovided with shelf 20. Lower portion 22 is configured to at leastpartially support deck 17 and/or wash basin 18. Preferably, lowerportion 22 is configured to conceal the conduit system fluidly couplingfixtures 14 to the fluid supply. Lower portion 22 may include one ormore access panels (such as a cabinet door) for allowing access to thecomponents of lavatory system 10 (e.g., conduit system, fixture controlsystem, etc.). According to various alternative embodiments, lowerportion 22 may be eliminated if deck 17 and/or wash basin 18 can besufficiently supported by other means, such as by mounting deck 17and/or wash basin 18 to a wall in a cantilever manner and/or bysupporting deck 17 and/or wash basin 18 with a structure provided fromabove lavatory system 10.

FIGS. 8 through 16 show control system 50 and components thereofaccording to exemplary embodiments. Control system 50 provides for the“hands-free” operation of fixtures 14. Control system 50 is a relatively“low” power system that is configured to avoid false readings that limitthe effectiveness of conventional control systems. Control system 50generally includes power supply system 100, detection system 200, andfixture actuation system 500. Power supply system 100 provides anoperating voltage to the various elements/components of control system50, while detection system 200 monitors an area (i.e., sensing region,zone of detection, etc.) adjacent fixture 14 and provides an outputsignal to fixture actuation system 500 which in turn activates ordeactivates a valve (e.g., a solenoid valve 502) for controlling theflow of a fluid through fixtures 14.

Control system 50 can be mounted to lavatory system 10 in a variety ofways and at a variety of positions. Preferably, the majority of thecircuitry of control system 50 is provided beneath wash basin 18 and isconcealed from the view of a user by lower portion 22 of supportstructure 12. According to various alternative embodiments, controlsystem 50 may be provided at a position that is remote from lavatorysystem 10. A sensory window 24 (shown in FIG. 1) is provided on lavatorysystem 10 to house and/or protect a transmitter 220 and an receiver 230of detection system 200. Lavatory system 10 is shown as having aseparate sensory window 24 for each fixture 14. According to variousalternative embodiments, a common sensory window 24 may be provided forhousing and/or protecting components of detection system 200 used tocontrol both fixtures 14. Sensory window 24, in combination withtransmitter 220 and receiver 230 of detection system 200, define thesensing region in which an object must enter in order for control system50 to activate fixtures 14. The size of the sensing region can be varieddepending on the particular application.

Referring particularly to FIGS. 9, 10, 15 and 16, power supply system100 generally includes a power source 102, a voltage regulator 104, acharging circuit 106, an energy storage element 108, and a voltagedetector 110. Power supply system 100 is configured to provide a firstoutput, shown as a system supply voltage 114, for providing electricalenergy to components of detection system 200, a second output, shown asa fixture supply voltage 116, for providing electrical energy to fixtureactuation system 500, and a third output, shown as a status signal 118,representative of power level of energy storage element 108. Accordingto various alternative embodiments, power supply system 100 may includeany number of outputs depending upon the requirements of control system50 and/or lavatory system 10.

Control system 50 is advantageously configured for use in applicationsfor which access to a conventional AC power line (requiring a hard-wiredconnection) is not readily available or is otherwise undesirable to use(e.g., not cost effective to access, etc.). While a conventional ACpower line may be used alone or in combination as power source 102,preferably power source 102 is an energy storage element having arelatively finite service or operating life such as a battery, aphotovoltaic cell energizing a capacitor (shown in FIG. 10), or thelike. According to a one embodiment, power source 102 is a lithiumbattery having a voltage between approximately 4 volts and approximately7 volts. According to various alternative embodiments, power source 102may be provided by any suitable battery having a range of suitablevoltages, and/or may further include a supplemental (e.g., secondary,etc.), a startup, and/or a backup power source.

According to a particularly preferred embodiment, power source 102 hasan output voltage of approximately 7 volts. Voltage regulator 104 isconfigured to adjust the output voltage of power source 102 to apredetermined operating voltage that is compatible with the componentsof detection system 200 before the electrical energy is outputted assystem supply voltage 114. According to an exemplary embodiment, voltageregulator 104 provides a relatively stable operating voltage ofapproximately 3.3 volts that is subsequently distributed as systemsupply voltage 114 to various components of control system 50 requiringelectrical energy (shown as system supply voltage inputs 120). Accordingto various alternative embodiments, voltage regulator 104 may beeliminated if the voltage of power source 102 equals the voltage neededfor system supply voltage 114.

Fixture supply voltage 116 (the second output voltage of power supplysystem 100) provides an operating voltage for the activation anddeactivation of a valve controlling the flow of a fluid from fixtures14. Fixture supply voltage 116 is outputted from energy storage element108, which is preferably provided by a storage capacitor. Energy storageelement 108 stores electrical energy until needed to actuate the valvecontrolling the flow of the fluid from fixtures 14. According to anexemplary embodiment, energy storage element 108 has a capacitance ofbetween approximately 10 millifarads (mF) to approximately 10 F.According to a preferred embodiment, energy storage element 108 isprovided by a single super capacitor having a capacitance ofapproximately 60 mF, but alternatively, may be provided by a pluralityof capacitors (the combination of which provides the desired capacitanceand voltage rating). According various alternative embodiments, energystorage element 108 may be configured to have a variety of capacitancesdepending upon the particular application.

To ensure that energy storage element 108 contains a sufficient amountof electrical energy to turn fixtures 14 on and/or off (i.e., enoughelectrical energy to actuate a solenoid valve 502), voltage detector 110is provided for monitoring the power level of energy storage element108. Voltage detector 110 monitors energy storage element 108 to ensurethat the voltage of energy storage element 108 does not drop below apreset threshold or baseline voltage. According to a preferredembodiment, the baseline voltage of energy storage element 108 is set atapproximately 4.5 volts (meaning that if the voltage of energy storageelement 108 drops below 4.5. volts, energy storage element will becharged sufficiently charged).

Voltage detector 110 sends status signal 118 (the third output of powersupply system 110) to detection system 200, preferably a computingdevice (shown as a central processing unit (CPU) 240) of detectionsystem 200, representative of power level of energy storage element 108.If status signal 118 indicates that the power level of energy storageelement 108 has dropped below the preset baseline voltage, CPU 240 sendsan output signal 122 to charging circuit 106 which is in turn activatedto charge energy storage element 108. Power supply system 100 mayoptionally include an indicator 112 (shown in FIGS. 12 and 13) toprovide for a visual display (e.g., a continuous or flashing light,etc.) when energy storage element 108 is being charged by chargingcircuit 106.

Referring generally to FIGS. 11 through 13, 15, and 16, detection system200 generally includes a computing device (shown as a central processingunit (CPU) 240) and a sample and hold circuit 210 to which a sensorydevice with a transmitter 220 and a receiver 230 is connected thereto.Detection system 200 further includes a pulse regulator circuit 260 forshortening the time interval of the sample period. Detection system 200monitors the sensing region and provides output signal to fixtureactuation system 500 indicating whether solenoid valve 502 should beopened or closed.

Referring particularly to FIGS. 11 and 15, CPU 240 is configured tosupport and execute a program to control the components of controlsystem 50. CPU 240 is powered by system supply voltage 114 and is shownas having a first output 242 for controlling transmitter 220, a secondoutput 244 for sending an operating voltage to receiver 230, a thirdoutput 246 for providing a “valve closed” signal to fixture actuationsystem 500, a fourth output 248 for providing a “valve open” signal tofixture actuation system 500, a fifth output 250 for controllingcharging circuit 106 of power supply system 100, a sixth output 252 foractivating indicator 112 when charging circuit 106 is charging energystorage element 108, and a seventh output 254 for providing an operatingvoltage to components of detection system 200. CPU 240 is further shownas having a first input 241 representative of the operating state offixtures 14, a second input 243 representative of the voltage level ofenergy storage element 108, and a third input 245 representative of thelevel of infrared light within the sensing region. According to variousalternative embodiments, CPU 240 may include any number of outputs andinputs to meet the requirements of the particular application.

CPU 240 is configured to operate at a relatively fast processing speedin comparison to CPUs used in known control systems which also rely upona power source having a relatively finite operating life. By utilizing aCPU having a relatively fast processing speed, control system 50 is ableto conserve power. Although a faster CPU requires more power thanconventionally used CPUs (those having a clock rate of less than 32kHz), the faster CPU is able to process third input 245 and compare thatvalue with an established baseline value to determine what output (thirdoutput 246 or fourth output 248), if any, should be sent to fixtureactuation system 500 faster than conventionally used CPUs.

According to an exemplary embodiment, CPU 240 has a clock rate greaterthan approximately 32 kilohertz (kHz). According to a preferredembodiment, CPU 240 has a clock rate within the range of approximately32 kHz to approximately 20 megahertz (MHz). According to a particularlypreferred embodiment, CPU 240 has a clock rate of approximately 4 MHz.Since a 4 MHz CPU can process and compare the signal faster than a 32kHz CPU, the sleep period of the 4 MHz CPU will be longer than that ofthe 32 kHz CPU. A longer sleep period will prolong the operating life ofenergy storage element 108. The sleep period may include periods whereinCPU 240 requires substantially no power and/or periods wherein CPU 240requires a reduced amount of power. For example, CPU 240 may beconfigured to operate between varying frequencies rather than justbetween an “on” and “off” operational state. Accordingly, CPU 240 mayhave a clock rate of 4 MHz while a sample of the sensory region is beingobtained, while having a clock rate of only 32 kHz between samplingperiods to allow for reduced power consumption. In such a configuration,the period during which the 4 MHz CPU operated at 32 kHz may constitutethe sleep period.

Referring generally to FIGS. 11 through 13, 15, and 16, transmitter 220is configured to emit a signal into the sensing region, while receiver230 is configured to measure (e.g., capture, monitor, etc.) the signalin the sensing region. Preferably, transmitter 220 is configured to emitpulses of infrared light into the sensing region, while receiver 230 isconfigured to measure the level of infrared light in the sensing region.According to various alternative embodiments, transmitter 220 andreceiver 230 may be configured as a radar sensor, a sonar sensor, or anyother suitable sensory device.

Receiver 230 may be operated independently of transmitter 220 (tomeasure a background level of infrared light) and/or may be operated inconjunction with transmitter 220 (to measure the amount of reflectedinfrared light in the sensing region to detect the presence of an object(e.g., a user)). When a user enters the sensing region, at least aportion of the infrared light emitted from transmitter 220 will bereflected by the user and detected by receiver 230. A signalrepresentative of the level of infrared light in the sensing region issent to CPU 240 which in turn uses the signal to determine whetherfixture actuation system 500 should be actuated. If an object isdetected, CPU 240 will send a signal from output 248 to fixtureactuation system 500 to activate a valve (e.g., solenoid valve 502)allowing for the flow of a fluid from at least one of fixtures 14.

Referring particularly to FIG. 12, transmitter 220 is shown as includinga power storage circuit 222, a current limiting switch 224, and an lightemitting diode (LED) 226. Power storage circuit 222 receives and storesa sufficient amount of power for activating LED 226. According to anexemplary embodiment, power storage circuit 222 includes a capacitorthat is charged by system supply voltage 114 outputted by power supplysystem 100. Current limiting switch 224 is provided for regulating themaximum current being provided to LED 226. According to an exemplaryembodiment, current limiting switch 224 limits the current going to LED226 to between approximately 700 and 800 milliamps.

According to an exemplary embodiment, one transmitter 220 having one LED226 is provided for each fixture 14. According to various alternativeembodiments, any number of transmitters 220 (having any number of LEDs226) can be used to emit pulses of infrared light into the sensingregion of the respective fixture 14. According to an exemplaryembodiment, LED 226 is supported at a position above fixtures 14 so thata fluid flow discharging from fixtures 14 does interfere with (e.g.,reflect, etc.) the pulses of infrared light being emitted by LED 226.Preferably, LED 226 is protected behind sensory window 24 (see FIGS. 1and 2) that is provided in upper portion 16 of support structure 12. Theplacement of LED 226 and/or sensory window 24 and the method ofsupporting LED 226 and/or sensory window 24 relative to supportstructure 12 may change depending on the fixtures and configuration oflavatory system 10.

Referring particularly to FIG. 13, receiver 230 is shown as including aphotodiode 232 and a photodiode amplifier 234. Photodiode 232 capturesthe level of infrared light in the sensing region (including levels ofinfrared light in the ambient light and/or levels of infrared light fromtransmitter 220). According to an exemplary embodiment, photodiode 232is positioned adjacent to LED 226. According to various alternativeembodiments, receiver 230 may include any number of photodiode 232 forcapturing the level of infrared light in the sensing region, and can bepositioned near and/or at a distance from LED 226. Photodiode 232generates an output signal 236 representative of level of infrared lightin the sensing region. Output signal 236 is fed into photodiodeamplifier 234, which is configured to amplify the current coming fromphotodiode 232 (output signal 236) into an analog voltage and to providebuffering for the resultant signal. The analog voltage representative ofthe level of infrared light in the sensing region is then sent to sampleand hold circuit 210.

Referring to FIGS. 11, 15, and 16, sample and hold circuit 210 isconfigured to receive and store a first voltage representative of thelevel of infrared light in the sensing region when transmitter 220 isnot activated and a second voltage representative of the level ofinfrared light in the sensing region when transmitter 220 is activated.Sample and hold circuit 210 is shown as including a first output 211 foroutputting the first voltage to a first buffer 212 and subsequently adifference amplifier 213. Sample and hold circuit 210 is further shownas including a second output 214 for outputting the second voltage to asecond buffer 215 and subsequently difference amplifier 213. Sample andhold circuit 210 includes one capacitor and one corresponding switch foreach the first voltage (representative of the level of infrared light inthe sensing region when transmitter 220 is not activated) and the secondvoltage (representative of the level of infrared light in the sensingregion when transmitter 220 is activated). Preferably, the storagecapacitors of sample and hold circuit 210 are relatively small so thatthe capacitors can charge quickly thereby allowing the input signalsfrom photodiode amplifier 234 to be continually recognized. According toa particularly preferred embodiment, storage capacitors having acapacitance of approximately 1000 picofarads (pF) are used for thestorage capacitors of sample and hold circuit 210. According to variousalternative embodiments, storage capacitors having other capacitancesmay be used.

Referring still to FIGS. 11, 15, and 16, pulse regulator 260 establishesthe time interval of a sample period for sample and hold circuit 210.For purposes of this disclosure, the term “sample period” is usedgenerally to refer to the period of time needed for sample and holdcircuit 210 to capture and hold both the background level of infraredlight and the background level of infrared light plus the reflectedlevel of infrared light. Pulse regulator 260 provides for a shortensample period (a sample period of approximately 1.5 microseconds (μs))that advantageously allows lavatory system 10 to be used in environmentswherein the ambient light and/or other signal transmitters at leastperiodically emit levels of infrared light. For example, it is generallyknown to use fluorescent lamps having a frequency range between 50 Hertz(Hz) and 110 kilohertz (kHz). If a measurement of the sensing region istaken over a relatively long period of time, the measurement may includea high peak value and a low peak value of the fluorescent light whichmay cause control system 50 to misinterpret the change in the level ofinfrared light in a sensing region. Shortening the sample perioddecreases the likelihood of a false reading caused by interferinginfrared light.

Pulse regulator 260 is shown as generally including a first monostable262 and a second monostable 264. First monostable 262 includes an input266 for receiving a signal from output 242 of CPU 240 for starting atiming period, a first output 268 for sending a signal to sample andhold circuit 210, and a second output 270 for providing a signal tosecond monostable 264. Second monostable 264 includes an input 272 forreceiving a signal from second output 270 from first monostable 262 andan output 274 for providing a signal to sample and hold circuit 210 andtransmitter 220. Together, first monostable 262 and second monostable264 provide a dual monostable multivibrator between an output pulse fromCPU 240 and transmitter 220 for shortening the sample period.

Referring particularly to FIGS. 14 through 16 fixture actuation system500 receives an input signal from detection system 200 indicatingwhether to change the operating state of fixtures 14. Fixture actuationsystem 500 is shown as generally including a valve, shown as a solenoidvalve 502, fluidly coupled to a fluid line between the fluid source andthe outputs of fixtures 14. Solenoid valve 502 switches between an firstor open position, wherein fluid is able to discharge from fixtures 14,and a second or closed position, wherein solenoid valve 502 isconfigured to block the fluid line to prevent fluid from dischargingfrom fixtures 14.

According to a preferred embodiment, solenoid valve 502 is a latchingvalve including a cylinder enclosing a piston having a plunger disposedaround a first end and a magnet positioned at the top of the first end.In the closed position, the plunger is seated against a diaphragm toprevent fluid from exiting fixture 14. In the open position, the plungeris unseated from the diaphragm and moved towards the top of the cylinderto allow for the flow of a fluid. The plunger is held in the openposition by the magnet.

Fixture actuation system 500 is further shown as including a switchingdevice, shown as an H-Bridge 504, for controlling the positioning ofsolenoid valve 502 by reversing the polarity of the current sent tosolenoid valve 502 from energy storage element 108. H-Bridge 504 isshown as including a first input 506 for receiving the “valve close”signal from output 246 of CPU 240, a second input 508 for receiving the“valve open” signal from output 248 of CPU 240, and a third input 510for fixture supply voltage 116 from energy storage element 108 of powersupply system 100. H-Bridge 504 is further shown as including a firstoutput 512 for providing a signal to solenoid valve 502 and a secondoutput 514 for providing a signal to CPU 240 representative to theoperational state of solenoid valve 502. Before reaching CPU 240, thesignal passes through an amplifier 516.

According to various alternative embodiments, CPU 240 may be configuredfor providing “valve open” signal to H-Bridge 504 without providing a“valve closed” signal. In this manner, solenoid valve may be closed byutilizing a timer to control the duration that solenoid valve 502 in theopen position.

Operation of control system 50 is described according to a particularlypreferred embodiment with reference to lavatory system 10. In operation,CPU 240 supports and executes a program to control the components ofcontrol system 50 by performing a series of statuses in a continuousloop. Upon startup, CPU 240 enters an initial status (e.g. power up,startup, etc.) wherein CPU 240 ensures that solenoid valve 502 is in thesecond or closed position so that fluid is not being discharged fromfixtures 14. CPU 240 ensures that solenoid valve 502 is in the closedposition by providing the “closed valve” signal from output 246 toH-Bridge 504 of fixture actuation system 500. During this initialstatus, CPU 240 further receives an input signal (status signal 118)from voltage detector 110 indicating whether energy storage element 108is sufficiently charged to actuate solenoid valve 502 (e.g., has avoltage of at least 4.5 volts, etc.) or is in need of charging. If theenergy level of energy storage 108 is below the preset baseline voltagestored within CPU 240, CPU 240 provides a signal from output 250 tocharging circuit 106 indicating that charging circuit 106 should beactivated for charging energy storage element 108. Energy storageelement 108 should be charged an amount sufficient to provide formultiple actuations of solenoid valve 502. While charging circuit 106 ischarging energy storage element 108, CPU 240 sends signal from output252 to activate indicator 112 to provide for a visual display thatenergy storage element 108 is being charged.

Once energy storage element 108 is sufficiently charged (registers avoltage greater than approximately 4.5 volts), and solenoid valve 502 isplaced in the closed position, detection system 200 establishes abaseline infrared light level for the sensing region that will stored inCPU 240 and which will be compared to later obtained signals todetermine if an object is within the sensing region. The baselineinfrared light level of the sensing region is established by taking asensing sample (i.e., comparing the background level of infrared lightin the sensing region with the reflected level of infrared light in thesensing region) or a number of sensing samples which is then stored inCPU 240. According to a particularly preferred embodiment, CPU 240 ispowered approximately every 0.25 seconds to check the charge on energystorage element 108 and the level of infrared light in the sensingregion and adjust the baseline value accordingly.

CPU 240 then enters a status referred to as a sensing cycle. During thesensing cycle, CPU 240 checks the charge of energy storage element 108and depending upon the charge turns charging circuit 106 on or off. CPU240 also checks the duration of time it has been since that lastactivation of solenoid valve 502 to adjust the time interval betweensample periods accordingly. According to a particularly preferredembodiment, if solenoid valve 502 has been activated within 30 minutes,a sample of the sensing region will be taken every 0.25 seconds.However, if solenoid valve 502 has not been activated for a periodgreater than 30 minutes, CPU 240 will take a sample of the sensingregion approximately every second in an effort to reduce powerconsumption. According to various alternative embodiments, CPU 240 maybe programmed in a variety of ways in order to minimize powerconsumption when fixtures 14 have not been in use for extended periodsof time.

CPU 240 then detects whether the level of infrared light in the sensingregion has changed relative to the baseline value that is stored in CPU240. Once the level of infrared light in the sensing region changes by apredetermined amount (i.e., an indication that an object is within thesensing region), CPU 240 sends the appropriate output signal (either asignal from output 248 to open solenoid valve 502 or a signal fromoutput 246 to close solenoid valve 502).

During one sensing cycle, CPU 240 sends a signal from output 242 tofirst monostable 262. Upon receiving a signal from output 242 of CPU240, first monostable 262 starts a timing period. According to anexemplary embodiment, the start of the timing period closes a firstswitch of sample and hold circuit 210 (a switch between photodiodeamplifier 234 and a first capacitor of sample and hold circuit 210).Once the first switch is closed, photodiode amplifier 234 provides anoutput voltage representative of the background level of infrared lightin the sensing region to the first capacitor of sample and hold circuit210. At this point, LED 226 of transmitter 220 is not emitting a pulseof infrared light and therefore the only infrared light being detectedand captured by receiver 230 is from the ambient light or other sensingsignals in the sensing region.

First monostable 262 latches the background infrared level when firstoutput 268 from first monostable 262 goes low. When first output 268goes low, second output 270 from first monostable 262 goes high whichtriggers second monostable 264. Upon activation, second monostable 264provides a signal from output 274 which activates transmitter 220 andcloses a second switch of sample and hold circuit 210 (a switch betweenphotodiode amplifier 234 and a first capacitor of sample and holdcircuit 210) to store the output voltage coming out of photodiodeamplifier 234 (i.e. the output voltage represents the background levelof infrared light). The second switch is held closed for a time intervalsufficient to provide a control pulse to transmitter 220. According toan exemplary embodiment, the second switch is held closed for a periodof approximately 1.5 μs. At the same time, LED 226 of transmitter 220emits pulses of infrared light into the sensing region. Afterapproximately 1.5 μs, the second switch of sample and hold circuit 210is opened and LED 226 is turned off. Advantageously, the sample periodis therefore accomplished in a relatively short period (i.e.approximately 1.5 μs).

There are two outputs from sample and hold circuit 210 (first output 211and second output 214). First output 211 outputs the voltage stored inthe first capacitor representative of the background level of infraredlight (i.e., the level of infrared light in the sensory region whentransmitter is not activated). Second output 214 outputs the voltagestored in the second capacitor representative of the background level ofinfrared light plus the level of infrared light while LED 226 wasemitting pulses of infrared light. First output 211 and second output214 are buffered through their respective buffers 212, 215 andsubsequently fed into difference amplifier 213. Out of differenceamplifier 213, a voltage representing only the reflected level ofinfrared light that was measured is provided. That value is fed intoinput 245 of CPU 240 for comparison with the baseline value storedtherein. The value is held long enough by CPU 240 so that CPU 240 canmeasure the voltage (compare the reflected level of infrared light withthe baseline value). According to an preferred embodiment, CPU 240 takesapproximately 19 μs to determine whether the reflected level of infraredlight is higher than the established baseline value and whether a signalshould be sent to fixture actuation system 500.

In comparing the reflected level of infrared light with the baselinevalue, CPU 240 is programmed to recognize a slight increase in theinfrared level as only a drift which can be used to adjust the baselinelevel. If a large increase in reflected infrared light is detected (e.g.when an object is within the sensing region), CPU 240 sends a signalfrom output 248 to fixture actuation system 500 to activate solenoidvalve 502.

The acquisition of the reflected level of infrared light takes about 1millisecond (ms). After that period CPU 240 is turned off until the nextcycle. According to a preferred embodiment, CPU 240 is turned off forapproximately 0.25 seconds. As a result, CPU 240 is on for approximately1 millisecond (ms) and is off for 250 ms. This is possible because ofthe shorten sample period for measuring the sensing region (e.g. 1.5μs). The remainder of the time is due to the power up time of the othercomponents (e.g., photodiode amplifier takes about 100 μs to get astable output value). Advantageously, control system 50 is conservingpower during the 250 ms sleep period. If LED 226 remains on for a longersample period (e.g., a sample period of 9 μs or greater), LED 226 willundesirably consume more power.

To activate solenoid valve 502, CPU 240 sends a signal from output 248to H-Bridge 504 indicating that solenoid should be moved to the openposition. H-bridge 504 further receives fixture supply voltage 116 fromenergy storage element 108 of power supply system 100 for providing thenecessary electrical energy to move solenoid valve 502. H-bridge 504flips the polarity of current coming from energy storage element 108 toopen solenoid valve 502. According to an exemplary embodiment, solenoidvalve 502 will remain open until the “closed valve” signal is sent byCPU 240 (when the level of infrared light measured in the sensing regionindicate that a user is no longer present). Control system 50 mayoptionally include a timer configured to send a signal to H-Bridge 504indicating that solenoid valve 502 should be moved to the closedposition after an established period of time, even if the “closed valve”signal is not sent by CPU 240.

FIGS. 2 through 7, 10, and 16 through 18 show photovoltaic system 600and components thereof according to exemplary embodiments. Photovoltaicsystem 600 capable of converting ambient light energy into electricalenergy that can be used to power a fixtures 14, and/or a control systemcoupled to fixtures 14 (such as control system 50). Photovoltaic system600 generally includes one or more photovoltaic cells 602 configured toconvert ambient light energy into electrical energy and a powermanagement system 650 providing for an efficient use of the electricalenergy generated by photovoltaic cells 602. FIG. 16 shows photovoltaicsystem 600 is as power source 102 of power supply system 100 of controlsystem 50.

Referring particularly to FIGS. 2 through 7, photovoltaic system 600includes one or more photovoltaic cells 602 (e.g., panels, elements,etc.), shown as an array of photovoltaic cells 602, that are capable ofconverting energy from ambient light into electrical energy. Dependingon the particular location of lavatory system 10, ambient light mayinclude artificial light (e.g., fluorescent, incandescent, halogen,etc.), natural light (sunlight), or a combination of artificial andambient light. Preferably, photovoltaic cells 602 are capable ofconverting varying wavelengths of light into electrical energy (e.g.,artificial light and natural light), but alternatively may be selectedfor being able to convert particular wavelengths of light intoelectrical energy. Photovoltaic system 600 represents an alternativepower source to an AC power line. Unlike an energy storage element(e.g., a battery), photovoltaic system has a relatively infinite life solong as there is sufficient intensity of ambient light.

Photovoltaic cells 602 are coupled to lavatory system 10 at a position(e.g., location, orientation, etc.) that exposes photovoltaic cells 602to ambient light, and preferably, at a position that maximizes theirexposure to ambient light. Photovoltaic cells 602 may be supported by,mounted to, contained within, and/or integrally formed with a portion oflavatory system 10. Photovoltaic cells 602 may be provided at a varietyof positions including, but not limited to, support structure 12,fixtures 14, deck 17, and/or basin 18. According to various alternativeembodiments, photovoltaic cells 602 may be positioned at a distance awayfrom lavatory system 10. For example, photovoltaic cells 602 may beprovided on a wall, partition, a mirror, etc. and electrically coupledto fixtures 14 and/or control system 50 via a suitable wiringconfiguration.

According to a preferred embodiment, photovoltaic cells 602 are coupledto a relatively flat surface of lavatory system 10 (e.g., shelf 20,etc.) that is likely to be laterally incident with the ambient light(i.e., perpendicular with the ambient light), but alternatively, may bepositioned in any of a variety of positions, angles, and/or orientationsdepending on the application. According to a further alternativeembodiment, photovoltaic cells 602 may be coupled to a curved surfacesuch as a basin 18, and/or a curved ledge or platform.

The configuration of lavatory system 10 (such as size and shape) willlikely dictate the locations at which photovoltaic cells 602 will bepositioned. FIG. 2 shows photovoltaic cells 602 coupled to lavatorysystem 10 at a raised (e.g., elevated, heightened, offset, etc.)position relative to the other components of lavatory system 10.Photovoltaic cells 602 are shown coupled to shelf 20 of supportstructure 12 which is positioned above fixtures 14. Shelf 20 is anelevated surface that is not likely to have a relatively permanentobstruction (e.g., fixture, support structure, etc.) positioned betweenits top surface and the ambient light source which may limit theexposure of photovoltaic cell 602 to the ambient light source.

FIG. 3 is a top view of lavatory system 10 showing photovoltaic cells602 coupled to shelf 20. Photovoltaic cells 602 are shown as beingdivided into three groups or segments of photovoltaic cells, butalternatively, may be provided as one continuous segment of photovoltaiccells or as individual photovoltaic cells. The number of photovoltaiccells 602 coupled to lavatory system 10 may vary depending on a numberof factors including, but not limited, the available surface area oflavatory system 10 capable of accepting photovoltaic cells 602, thepower requirements of the control system and/or fixtures 14, the outputand efficiency of photovoltaic cells 602, and/or aestheticconsiderations.

According to an exemplary embodiment, it is desirable to maximize thenumber of photovoltaic cells 602 used with lavatory system 10 as isreasonably practical. For example, still referring to FIG. 3,photovoltaic cells 602 cover a substantial portion of the surface areaof shelf 20. According to various alternative embodiments, the number ofphotovoltaic cells 602 used may be limited rather than maximized. Theuse of commercially available photovoltaic cells 602 (e.g., photovoltaiccells have an established size) may constrain the number of photovoltaiccells coupled to lavatory system 10.

FIGS. 4 and 5 show a method of coupling photovoltaic cells 602 tolavatory system 10 according to an exemplary embodiment. Referringparticularly to FIG. 4, shelf 20 is shown having an aperture (e.g.,cavity, opening, channel, depression, etc.), shown as a recess 142,configured to receive photovoltaic cells 602. Shelf 20 may be formed(e.g., molded, cast, manipulated, etc.) with recess 142, oralternatively, material may be removed (e.g., milled, cut, drilled,shaved, etc.) from shelf 20 to provided recess 142. Preferably, recess142 has a depth sufficient so that when photovoltaic cells 602 arepositioned therein, the tops of photovoltaic cells 602 do not outwardlyextend above the top surface of shelf 20. Such a configuration may allowfor a relatively continuous surface once photovoltaic cells 602 acovered by a suitable coating.

Photovoltaic cells 602 are shown to include wires 605 used toelectrically couple photovoltaic cells 602 to fixtures 14 and/or acontrol system for controlling fixtures 14 or some other component oflavatory system 10. Preferably recess 142 includes an opening forallowing wires 605 to be routed to the desired location while concealingwires 605 from the view of a user.

FIG. 5 shows photovoltaic cells 602 as being coupled to shelf 20 via arelatively clear (e.g., transparent, translucent, etc.) sealer orcoating, shown as a resin 603. The coating may include, but is notlimited to, an epoxy, a polyester resin, or any other suitable materialthat can be added to recess 142 for coupling photovoltaic cells 602 andwill allow for sufficient levels of ambient light to pass through tophotovoltaic cells 602. In such a configuration, photovoltaic cells 602are substantially integrally formed with shelf 20. Shelf 20 may in turnbe permanently coupled to upper portion 16 of support structure 12, oralternatively, may be detachably coupled so that shelf 20 can be readilyremoved in the in event that photovoltaic cells 602 need to be replacedand/or repaired.

According to an exemplary embodiment, resin 603 is added to recess 142to couple photovoltaic cells to shelf 20. Preferably, resin 603 isdisposed on the tops of photovoltaic cells 602 to provide protection.According to a particularly preferred embodiment, a first layer of resin603 is disposed between photovoltaic cells 602 and shelf 20 and a secondlayer of resin 603 is disposed on top of photovoltaic cells. Such aconfiguration may help maintain the position and/or the integrity ofphotovoltaic cells 602 as resin 603 is added (e.g., poured, etc.) overthe tops of photovoltaic cells 602. After resin 603 is allowed toharden, resin 603 is preferably finished so that resin 603 issubstantially even in height with the top surface of shelf 20. Accordingto various alternative embodiments, resin 603 may only be applied overthe tops of, along the sides of, and/or beneath photovoltaic cells 602.

According to an alternative embodiment, photovoltaic cells 602 may bemounted to shelf 20. Photovoltaic cells 602 may be directly mounted toshelf 20, or alternatively, may be indirectly mounted to shelf 20.Photovoltaic cells 602 may be mounted to shelf 20 using any of a varietyof suitable methods including, but not limited to, mechanical fasteners(e.g., clips, screws, staples, brackets, collars, cover plates, etc.),adhesives, and/or any suitable welding process. The mounting ofphotovoltaic cells 602 may be intended to be relatively permanent, oralternatively, may be intended to be removable so that photovoltaiccells 602 readily removed and replaced (or repaired) if damaged.

To protect photovoltaic cells 602 from contaminants and/or manipulation(e.g., vandalism), a relatively clear member may be disposed overphotovoltaic cells 602. For example, a relatively clear (e.g.,transparent, translucent, etc.) glass member or plastic member (e.g.,acrylic, etc.) may be disposed over photovoltaic cells 602. Such amember may also be configured to at least partially secure photovoltaiccells 602 to shelf 20. The member may be a relatively rigid member, oralternatively may be a relatively flexible member such as a flexiblefilm, or some other suitable material.

FIGS. 6 and 7 show a method of coupling photovoltaic cells 602 tolavatory system 10 according to another exemplary embodiment. Lavatorysystem 10 is shown as being configured to support one or morephotovoltaic cell packages or units comprising a receptacle (shown as arelatively shallow pan or tray 604). Tray 604 is sized and dimensionedto receive one or more photovoltaic cells 602. Photovoltaic cells 602are coupled to tray 604, which is in turn coupled to lavatory system 10.

Trays 604 may be permanently coupled to lavatory system 10 or detachablycoupled to lavatory system 10. The use of photovoltaic cell units mayprovide for modularity in lavatory system 10, and allow photovoltaiccells 602 to be readily installed, removed, and/or interchanged. Such aconfiguration may allow photovoltaic cells 602 to be efficiently removedin the event that photovoltaic cells 602 are to be repaired or replaced.Preferably, the photovoltaic cell units are coupled to lavatory system10 from an area generally not accessible to a user (e.g., from thebottom of shelf 20) in an attempt to protect from (or minimize theeffect of) tampering and/or vandalism and/or other known harm tophotovoltaic cells 602.

Tray 604 is shown as being coupled to shelf 20 of support structure 12and received within recess 142. Referring to FIG. 7, photovoltaic cells602 are coupled to tray 604 using resin 603. According to a preferredembodiment, photovoltaic cells 602 are inserted in tray 604 and resin603 is disposed over the tops of photovoltaic cells 602 and allowed toharden. The resultant photovoltaic cell units may then be coupled toshelf 20.

FIGS. 10 and 16 show a block diagram of control system 50 incorporatingphotovoltaic system 600 as power source 102. It should be noted thatphotovoltaic system 600 not limited in application to control system 50or other control systems designed to provide for “hands free” operationof a fixture. According to various alternative embodiments, photovoltaicsystem 600 may be used in combination with other forms of controlsystems and/or fixtures requiring or using electric energy in order tooperate (or assist in operation). For example, photovoltaic system 600may be configured to provide electrical energy to a control systemcoupled to a fixture having a user interface that is electricallyactuated (e.g., an electric push-button, a touch sensor, etc.).

FIG. 17 shows a detailed block diagram of power management system 650and components thereof according to an exemplary embodiment. Powermanagement system 650 advantageously provides for an efficient use ofthe electrical energy generated by photovoltaic cells 602. Powermanagement system 650 is shown as generally including an energy storageelement 660 configured to receive and store electrical energy generatedby photovoltaic cells 602, a detector 670 configured to measure thelevel (intensity) of ambient light, a switch 680 configured todisconnect energy storage element 660 from control system 50 if thelevel of ambient light drops below a predetermined value, and a voltageregulator 690 for adjusting the voltage being outputted to controlsystem 50.

According to an exemplary embodiment, energy storage element 660includes one or more capacitors suitable for receiving a electric chargefrom photovoltaic cells 602 and supplying an output voltage to controlsystem 50. According to a preferred embodiment, energy storage element660 includes a plurality of capacitors arranged in series to provide thedesired capacitance of approximately 3.3 farads (F). According to aparticularly preferred embodiment, energy storage element 660 includes afirst capacitor, a second capacitor, and a third capacitor. Firstcapacitor, a second capacitor, and a third capacitor are supercapacitors having a capacitance of approximately 10 F each or a combinedcapacitance of approximately 3.3 F. According to an alternativeembodiment, other numbers and/or types of capacitors may be used andsuch capacitors may be arranged in series and/or in parallel.

Energy storage element 660 may be fully charged or partially charged byphotovoltaic cells 602. The rate at which energy storage element 660 ischarged depends at least partially on the intensity of the ambient lightand the effectiveness (e.g., number, size, efficiency, etc.) ofphotovoltaic cells 602. During an initial setup (e.g., anytime energystorage element 660 is fully discharged), the time required to chargeenergy storage element 660 to a level sufficient to operate thecomponents of control system 50 may be relatively long. The chargingtime during the initial setup can be reduced by adding a supplementalpower source (e.g., a battery, etc.) to charge energy storage element660. The supplemental power source provides a “jump-start” for energystorage element 660, and may significantly reduce the charging time.Preferably, any supplemental power source is removed once energy storageelement 660 is sufficiently charged, but alternatively, may remaincoupled to the system but electrically disconnected from energy storageelement 660.

A fully charged energy storage element 660 is capable of providing asufficient amount of electrical energy to power control system 50 forthe selective operation of fixtures 14. According to an exemplaryembodiment, energy storage element 660 is capable of providing asufficient amount electrical energy to allow for more than oneactivation of fixtures 14 before energy storage element 660 needs to berecharged. According to a preferred embodiment, energy storage element660 can retain or hold a sufficient amount of electrical energy toprovide approximately 70 activations of fixtures 14 before needing to berecharged. As can be appreciated, in a typical application (e.g., anapplication wherein photovoltaic cells 602 are exposed to ambient lightwhile lavatory system 10 is being used), photovoltaic cells 602 willcontinue to charge energy storage element 660 as electrical energy isprovided for the activation of fixtures 14.

Control system 50 constitutes a load on energy storage element 660 thatwhen electrically coupled thereto diminishes the electrical energystored in energy storage element 660. Disconnecting energy storageelement 660 from such a load will help maintain the charge of energystorage element 660. To determine whether power should be conserved bydisconnecting control system 50 from energy storage element 660, powermanagement system 650 further includes voltage detector 670. Voltagedetector 670 includes an input 672 electrically coupled to an outputfrom photovoltaic cells 602. Voltage detector 670 also includes anoutput 674 electrically coupled to switch 680.

An output voltage is provided by photovoltaic cells 602. The magnitudeof the output voltage may be based upon the intensity of the ambientlight and the efficiency of photovoltaic cells 602. Voltage detector 670detects whether photovoltaic cells 602 are being exposed to a level ofambient light sufficient to meet the power demands of control system 50.According to an exemplary embodiment, a reference voltage value (abaseline value) representative of the sufficient level of ambient lightis maintained by voltage detector 670. Such a reference value may bechanged depending on the power requirements of control system 50.

According to an exemplary embodiment, if photovoltaic cells 602 are notbeing exposed to a sufficient level of ambient light, the assumption isthat lavatory system 10 is not in use (e.g., the lights have been turneddown and/or off) and that control system 50 does not need to be powered.In such a situation, control system 50 is disconnected from powermanagement system 650 in an effort to conserve electrical energy.According to a preferred embodiment, voltage detector 670 measures theoutput voltage of photovoltaic cells 602 (received at input 672) andcompares the output voltage with the reference voltage value. If theoutput voltage level is below the reference voltage level, voltagedetector 670 will send an output signal (at output 674) to switch 680indicating that control system 50 should be electrically disconnectedfrom power management system 650. According to various alternativeembodiments, voltage detector 670 may be replaced with any detectorsuitable for detecting the intensity of the ambient light atphotovoltaic cells 602 including, but not limited to, a photodetectorconfigured to monitor the ambient light and send a corresponding signalto switch 680.

Preferably, energy storage element 660 is capable of holding a chargewith minimal leakage when disconnected from the load (control system50). Providing energy storage element 660 that is capable of maintaininga charge with minimal leakage, may allow energy storage element 660 tomeet the electrical power requirements of control system 50 afterphotovoltaic cells 602 have not been exposed to ambient light for anextended period of time (e.g., a weekend, etc.). This will eliminate theneed to recharge energy storage element 660 (e.g., by a supplementalpower source and/or by photovoltaic cells 602, etc.), or at least reducethe time required to recharge energy storage element 602, when theambient light returns and a user seeks to use fixtures 14 of lavatorysystem 10. When voltage detector 670 measures a voltage at or above thepredetermined baseline voltage, switch 680 reconnects power managementsystem 650 to control system 50.

Power management system 650 is further shown as including voltageregulator 690 adapted for receiving a first voltage from photovoltaiccells 602 and providing a second voltage to control system 50. Accordingto an exemplary embodiment, voltage regulator 690 is capable ofproviding a relatively stable operating voltage to control system 50.According to an exemplary embodiment, voltage regulator 690 is shownschematically as a dc-to-dc converter. According to a preferredembodiment, the voltage entering the dc-to-dc converter may rangebetween approximately 1.5 volts and 7.5 volts, while the voltage exitingthe dc-to-dc converter is approximately 5 volts. As can be appreciated,the input and output voltages may vary in alternative embodiments.

It is important to note that the construction and arrangement of theelements of the lavatory system, including the fixtures, the controlsystem, and/or the photovoltaic system, as shown in the preferred andother exemplary embodiments are illustrative only. Although only a fewembodiments of the present inventions have been described in detail inthis disclosure, those skilled in the art who review this disclosurewill readily appreciate that many modifications are possible (e.g.,variations in sizes, dimensions, structures, and proportions of thevarious elements, values of parameters, mounting arrangements, etc.)without materially departing from the novel teachings and advantages ofthe subject matter recited herein. For example, For example, the circuitdiagrams provided are schematic only, and the values for the individualcomponents (e.g., the ratings for the resistors, capacitors, etc.) mayvary according to alternative embodiments. Further, while thedescription herein may suggest that a pulse generator is used to controlpulsing of the transmitter, such control may be accomplished by othermeans (e.g., software, programming, computations, algorithms, etc.).Even further, while the inventions described herein are described withreference to use washing stations, the inventions may be used with anyof a variety of different applications wherein a control system of thetype disclosed herein would be beneficial. Further, the position ofelements may be reversed or otherwise varied (e.g., the circuit diagrammay be modified or may be incorporated in other circuits), and thenature or number of discrete elements or positions may be altered orvaried. It should further be noted that the scope of the inventionsinclude all software conventionally known or suitable for use withproximity sensors. For example, the control system may be programmedwith failure modes for closing the valve if left open for an extendedperiod. Further, the control system may be programmed to providedextended sleep periods when the fixture has not been used for a settime. The control system may also be programmed to require two positivereads before the valve is opened.

The order or sequence of any process or method steps may be varied orre-sequenced according to alternative embodiments. Anymeans-plus-function clause is intended to cover the structures describedherein as performing the recited function and not only structuralequivalents but also equivalent structures. Other substitutions,modifications, changes and omissions may be made in the design,operating configuration and arrangement of the preferred and otherexemplary embodiments without departing from the spirit of theinventions as expressed in the appended claims.

1. A control system for use with a lavatory system for use by a userhaving at least one wash station and at least one electrically operatedfixture, the control system comprising: a detection system including acontrol circuit configured to operate during a first period during whicha sensing region is monitored for the presence of the user followed by asecond period during which power consumption by the control circuit isreduced; and a fixture actuation system coupled to the detection systemand configured to control the flow of a fluid through the fixture basedupon a signal received from the control circuit during the first periodwherein the second period is greater than the first period so that totalpower consumption by the control circuit can be reduced.
 2. The controlsystem of claim 1 wherein the second period is at least 100 timesgreater than first period.
 3. The control system of claim 2 wherein thesecond period is between approximately 100 milliseconds andapproximately 400 milliseconds and the first period is betweenapproximately 0.5 milliseconds and approximately 2 milliseconds duringthe cycle period.
 4. The control system of claim 3 wherein the secondperiod is approximately 250 milliseconds and the first period isapproximately 1 millisecond.
 5. The control system of claim 1 whereinthe control circuit comprises a processor.
 6. The control system ofclaim 5 wherein the processor is a central processing unit having aclock rate greater than approximately 32 kilohertz (kHz).
 7. The controlsystem of claim 6 wherein the central processing unit has a clock rateranging from approximately 32 kHz to 20 megahertz (MHz).
 8. The controlsystem of claim 1 wherein the fixture actuation system comprises a valveconfigured to control the flow of fluid through the at least onefixture.
 9. A control system for use with a lavatory system for use by auser having at least one wash station and at least one electricallyoperated fixture, the control system comprising: a control circuit; asensor coupled to the control circuit and including a transmitter and areceiver configured to the user within a sensing region; and a samplingcircuit coupled to the control circuit and the sensor and configured tostore a first signal and a second signal from the receiver; wherein adifference between the first signal and the second signal is received bythe control circuit for determining whether to activate the fixture. 10.The control system of claim 9 further comprising a device configured toreceive a pulse from the control system and to provide a first output tothe sampling circuit and a second output to a second device configuredto provide a first output to the sampling circuit and a second outputfor activating the transmitter.
 11. The control system of claim 10further comprising a power supply, wherein the power supply includes atleast one of a battery, a photovoltaic cell, or combinations thereof.12. The control system of claim 9 further comprising a fixture actuationsystem having a switch electrically coupled to a valve and configured toreceive an input signal from the processor representative of the desiredposition of the valve.
 13. The lavatory system of claim 9 wherein thetransmitter is configured to emit pulses of infrared light into thesensing region and the receiver is configured to measure the level ofinfrared light in the sensing region, wherein the sampling circuitincludes a first capacitor configured to store the first signalrepresentative of the level of infrared light in the sensing region whenthe transmitter is not emitting infrared light and a second capacitorconfigured to store the second signal representative of the level ofinfrared light in the sensing region when the transmitter is emittinginfrared light.
 14. A power supply system for a lavatory system having acontrol system for operating a fixture, the power supply systemcomprising: a power source configured to be electrically coupled to thecontrol system and to provide an output voltage; a detector configuredto monitor the output voltage of the power source; and a switchconfigured to electrically disconnect the power source from the controlsystem when the output voltage of the power source drops below apredetermined level.
 15. The power supply system of claim 14 wherein thepower source is at least one photovoltaic cell configured to convertambient light energy into an output voltage.
 16. The power supply systemof claim 15 wherein the at least one photovoltaic cell is an array ofphotovoltaic cells.
 17. The power supply system of claim 16 furthercomprising an energy storage element electrically coupled between thephotovoltaic cell and the switch for storing the output voltagegenerated by the photovoltaic cell.
 18. The power supply system of claim17 wherein the energy storage element is a capacitor.
 19. The powersupply system of claim 14 further comprising a regulator for adjustingthe output voltage of the power source before being received by thecontrol system.
 20. A lavatory system comprising: a lavatory providingat least one wash station and having at least one basin and at least onefixture; a control system for controlling the flow of fluid to the atleast one fixture; an array of photovoltaic cells coupled to thelavatory and configured to provide power to the at least one fixture.21. The lavatory system of claim 19, wherein the lavatory is locatedabove the at least one fixture and includes a recess for receiving thearray of photovoltaic cells.
 22. The lavatory system of claim 20,wherein the array of photovoltaic cells are integrally formed with thelavatory.